Agromyza pudica Spencer

Eiseman, Charles S. & Lonsdale, Owen, 2018, New state and host records for Agromyzidae (Diptera) in the United States, with the description of thirty new species, Zootaxa 4479 (1), pp. 1-156 : 12

Agromyza pudica Spencer

( Fig. 74 )

Material examined. MASSACHUSETTS: Franklin Co., Northfield , 276 Old Wendell Rd. , 4.vii.2016, em . 21.vii.2016, C.S. Eiseman, ex Dichanthelium acuminatum ssp. fasciculatum , #CSE2787, CNC654200–654202 (1♂ 2♀); NORTH CAROLINA: Durham Co., Durham, 17 - Acre Wood Preserve, 15.v.2016, em. 4 , vi.2016, T.S. Feldman, ex Dichanthelium clandestinum , 4 larvae from 1 mine, #CSE2542, CNC654303–654306 (4♂); Durham, Stagecoach Road Eagle Spur Trail, 10.vii.2017, em. 5.viii.2017, T.S. Feldman, ex Dichanthelium , #CSE4076, CNC939831–939833 (2♀ 1 puparium); Scotland Co., Laurinburg, St. Andrews University , 11.v.2016, em. 3.vi.2016, T.S. Feldman, ex Dichanthelium scoparium , #CSE2540, CNC653948, CNC653949 (1♂ 1♀); 18.v.2016, em. 13.vi.2016, T.S. Feldman, ex Dichanthelium , #CSE2572, CNC634813–634815 (3♂); OHIO: Hocking Co. , South Bloomingville, Deep Woods Farm, 5.viii.2016, em . 20–22.viii.2016, C.S. Eiseman, ex Dichanthelium clandestinum , #CSE2925, CNC654480–654482 (1♂ 2♀).

Hosts. * Poaceae : Dichanthelium acuminatum (Sw.) Gould & C. A. Clark , D. clandestinum (L.) Gould, D. scoparium (Lam.) Gould.

Leaf mine. ( Fig. 74 ) Eggs are inserted near the leaf margin, associated with a cluster of feeding punctures. The larva initially mines along the margin almost to the apex, then turns around and forms a gradually widening, greenish-brown blotch with distinct concentric feeding lines. Dark, liquidy frass is deposited in a widening, more or less continuous central mass (or sometimes presenting a speckled appearance). A leaf may contain 1–4 mines originating from the same cluster of feeding punctures; in some cases the larvae maintain separate channels rather than forming a common mine. On the small leaves of Dichanthelium acuminatum , each leaf was mined by a single larva and the completed mine occupied the entire leaf surface.

Puparium. Yellow-orange to reddish-brown; formed outside the mine.

Distribution. USA: AR, GA, *MA, MN, NC, *OH.

Comments. The leaf mine of Agromyza pudica appears to be indistinguishable from that of A. parca , which also feeds on Dichanthelium . Agromyza pudica differs from the latter species in having a first flagellomere that is sometimes orange along the basal margin, the apex of the basiphallus is bifid (not linear) and without lateromedial membranous lobes, and the distiphallus is narrowest medially (not apically) and more strongly convoluted.

Figures

FIGURES 63–74. leaf mines; 63: Agromyza albitarsis Meigen in Populus balsamifera; 64: A. ambrosivora Spencer in Helianthus annuus; 65: A. aristata Malloch in Ulmus rubra; 66: A. bispinata Spencer in Elymus hystrix; 67: A. diversa Johnson in Laportea canadensis; 68: A. fission spec. nov. in Celtis occidentalis; 69: A. idaeiana Hardy in Geum macrophyllum; 70: A. isolata Malloch in Populus balsamifera, young mines (left) with probable A albitarsis mine at leaf margin; 71: same Populus balsamifera leaf with completed mines, A. isolata to left of midrib and probable A. albitarsis to right; 72: A. parca Spencer in Dichanthelium clandestinum; 73: A. pseudoreptans Nowakowski in Urtica dioica; 74: A. pudica in Dichanthelium scoparium.